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Turning the screw
Posted: January 20th, 2013, 11:13 am
by Trains
Any ideas of how to turn it? Also, i would like clarification on the screws axis
Re: Turning the screw
Posted: January 20th, 2013, 7:21 pm
by Jkwashbourne
We used a couple of 5/16" collets to attach the axle of a small DC motor to a piece of 1/8" threaded rod. Filed the rod and the axle down halfway and it works pretty well. but maybe a piece of string wound around with a weight might turn a screw if the bearings/bushings were good.
Re: Turning the screw
Posted: February 1st, 2013, 8:41 am
by SALIA
Jkwashbourne - when you use a motor, how do you start/stop the motor? Is there any picture available?
Re: Turning the screw
Posted: February 1st, 2013, 2:53 pm
by Jkwashbourne
we used microswitches, small switches with levers attached. here is one very similar to what we ordered. they are out of stock on the ones we used. sometimes there are clearance deals and prices go way down. these work great for DC.
http://www.allelectronics.com/make-a-st ... VER/1.html
Re: Turning the screw
Posted: February 1st, 2013, 2:54 pm
by Jkwashbourne
also, you can use that switch to open or close a circuit. we used one to start and one as a limit switch to stop the current
Re: Turning the screw
Posted: February 1st, 2013, 7:55 pm
by SALIA
Thanks. Do you use the same type of switch to stop and start the motor, or, there are different types of switches for start and stop?
Re: Turning the screw
Posted: February 1st, 2013, 8:43 pm
by Jkwashbourne
We used that same microswitch 4 times, sometimes for closing a circuit and sometimes for opening (limit switch).
Re: Turning the screw
Posted: February 9th, 2013, 9:34 am
by goodcheer
Trains wrote:Any ideas of how to turn it? Also, i would like clarification on the screws axis
A screw is technically an inclined plane wrapped around an axis. As the axis turns, the load travels along the inclined plane (the grooves of the screw) and moves closer to the head or farther away depending on the direction of rotation. For example, a nut on a screw would be traveling parallel to the screw's axis of rotation as the screw is rotated. Note: You have to keep the nut or the load from turning as you turn the screw in order for the load to move in a parallel direction. If you can find a plastic screw such as those found with kid's building toys these can be very useful because they can have very coarse threads. Ones with coarse threads do not have to turn as much to get the 2 cm movement required. Here is another idea: under-arm deodorant operates by turning a wheel attached to a long screw. Take an empty one (or partly empty whatever), carefully cut open one side, inspect it, use it (the screw assembly and housing that is and deodorant if neeeded:). You can attach a motor to the wheel or a pulley powered by a counter-weight. Note: Some operate more smoothly than others. Good luck.
Re: Turning the screw
Posted: February 12th, 2013, 5:04 pm
by Splicerblade
@goodcheer - thanks! does the setup you described call ball screw?
Re: Turning the screw
Posted: February 19th, 2013, 10:39 am
by goodcheer
Splicerblade wrote:@goodcheer - thanks! does the setup you described call ball screw?
Same principle. The screw is similar, but the nut or part that carries the load is different. On a ball screw it is more elaborate, more efficient, designed to minimize friction, etc.